1. Field of the Invention
This invention relates to a method of and an apparatus for making bread at home and, in particular, to a method of and an apparatus for making bread by which anybody can make flavorful bread through all seasons regardless of their knowledge of baking.
2. Description of the Prior Art
Generally, the break making process progresses in such steps that wheat flour, yeast, butter or shortening, sugar, salt, dry milk, and water as materials each in an appropriate quantity are prepared, kneaded in a vessel, subjected to the primary fermentation, degassed, subjected to the secondary fermentation to be optionally performed, degassed again, subjected to shaping-fermentation after the lapse of a waiting time (bench time), and baked into bread. The above process takes 3 to 4 hours and has hitherto solely depended on the manual operation, whereby home-baking has been followed by a problem that a housewife familiar with baking is obliged to be attentive thereto for 3 to 4 hours continuously and prevented from getting on with other houseworks. For solving such problems, the applicant of this invention filed a patent application for "automatic breakmaking apparatus" (Date of Application: June 28, 1984), and was granted a patent right as the U.S. Pat. No. 4,538,509. This "automatic breakmaking apparatus" was composed of: a material (-containing) vessel for containing bread materials; water supply means for supplying water for the material vessel; kneading means for kneading the dough disposed in the material vessel; a heater for baking the kneaded dough; a temperature sensor for sensing temperature variation in the dough under kneading; and a control part for controlling abovesaid several means and devices on the basis of information obtained from the temperature sensor, wherein the process progressing from kneading of dough to baking was automatically performed except feeding of bread materials each in a fixed quantity into the material vessel in the beginning and subsequent switching-on of the power source.
It is known that an important point in bread making is temperature control for the dough during kneading. The temperature of the dough when kneading is completed is preferably set to be approximate to the temperature at which gluten reaches the optimum level of glutinousness (which will be called "optimum kneading temperature" hereinafter). It is also known that the optimum kneading temperature for, for example, English bread ranges from about 27.degree. to 30.degree. C., and, therefore, the temperature of mixed materials of English bread before kneading is preferably set slightly lower than 27.degree. C. in consideration of the temperature rise caused in the material mixture by frictional heat during kneading.
As described above, in the case of English bread, gluten is in the best glutinous condition at a temperature between 27.degree. and 30.degree. C., not above or below, and various ideas, such as pouring of cold water into the material mixture in the summer in view of high atmospheric temperature or warm water in cold winter, have hitherto been employed for adapting the dough temperature at the end of kneading to be approximate to the optimum degree.
In the "automatic break-making apparatus" for which the inventor of this invention filed a patent application, too, the above method is adopted and water of normal temperature is poured into the material mixture in the spring and autum whereas cold water of about 5.degree. C. is used in the summer and warm water in the winter so that a temperature of the material mixture before the start of kneading may be set at 20.degree. to 22.degree. C. through all seasons. Practically, it is common to start kneading when the temperature of the material mixture is found reaching a level between 20.degree. and 22.degree. C. as a result of continuous monitoring of temperature by means of a temperature sensor disposed in an appropriate position in the material vessel. With the start of kneading, the temperature of the material mixture starts rising gradually due to the generation of frictional heat herein. Kneading is usually stopped at the supposed standard time when the rising temperature reaches a level between 27.degree. and 30.degree. C. at which the glutinousness of gluten becomes optimum.
Another method of lowering the temperature of the material mixture at the start of kneading in place of the use of cold water has also been disclosed, wherein a blower to blow air to the material mixture is provided in a suitable position in the oven so as to deprive the material of evaporation heat and thereby lower the temperature thereof.
By the method devised as above, the dough temperature at the time of completion of kneading can always be approximated to a degree between 27.degree. and 30.degree. C. at which yield of gluten of the highest quality is expectable and loaves of bread are soft and rich in flavor.
However, when having closely examined bread baked by this apparatus, it has been found that the bread quality is maintained at a certain level but varies in stiffness according to the atmospheric temperature in the day on which bread is baked even in the same season and also varies subtly in flavor. The applicant probed the causes of such differences and have found that the problem is attributable to the length of time of kneading. In other words, even in the same season, the atmospheric temperature differs according to the day and influences the speed of temperature rise in the dough which is caused by frictional heat during kneading, whereby a difference arises in the length of time of kneading even when the temperature rises by the same degree. Thus, even if the dough temperature is strictly controlled at the start and the end of kneading, the length of time of kneading varies as far as timing of the finish of kneading is set on the basis of the dough temperature only. Such relationship as above has been found to cause a difference in the ripening degree of gluten and to influence fermentation of the dough, resulting in subtle effects on stiffness and flavor of baked bread.